Saudi Arabia's permanent mission to the United Nations... formally requested the United Nations Secretary General notify the Security Council of the heinous conspiracy," the Saudi-owned Asharq al-Awsat newspaper reported, citing a statement from the kingdom's U.N. mission.

The U.S. on Tuesday said it had uncovered a plot by two men with links to Iran's security forces to assassinate Adel al-Jubeir by planting a bomb in a Washington restaurant.

One of the men, who had allegedly paid a U.S. undercover agent posing as a Mexican drug cartel hitman to carry out the assassination, has been arrested while the other is in Iran, the United States said.

Tehran has denied the charges.

The Saudi step follows remarks by U.S. President Barack Obama that he would press for "the toughest possible sanctions" against Iran over the alleged plot and vowed not to take any options off the table - a phrase commonly used to mean the possibility of using force.

Saudi Foreign Minister Prince Saud al-Faisal said on Wednesday in Vienna that Iran "was responsible" for the alleged plot and insisted the kingdom would adopt a "measured response".

Tensions between Shi'ite Muslim Iran and Sunni Saudi Arabia have risen in recent months as Arab uprisings have altered the balance of power in the Middle East.

Saudi Arabia earlier this month appeared to blame Iran, without naming it, for instigating clashes between members of the kingdom's Shi'ite minority and security forces on Oct 3 in which 14 people were injured.